A case with a center primer like that would be later than Civil War, I believe.
The earliest cartridge cases, some of which were used in the Civil War, had a primer inserted from the inside, and didn't show the primer like your cases do.
I can't tell you what the cartridge is without some detailed measurements of case length, rim diameter, and the case body diameter just ahead of the rim. The diameter of the case mouth is helpful, too, if you find any undamaged ones.
My guess is that your cases date from about 1875 or later.
